Improved singlet oxygen generation in rhenium(I) complexes functionalized with a pyridinyl selenoether ligand

Autor(es)

Morelli Frin, Karina P. ^[1] ; de Macedo, Leonardo Henrique ^[1] ; de Oliveira, Samuel Santos ^[1] ; Cunha, Rodrigo L. O. R. ^[1] ; Calvo-Castro, Jesus ^[2]

Afiliação do(s) autor(es)

^[1] Fed Univ ABC UFABC, Av Estados 5001, BR-09210170 Santo Andre, SP - Brazil

^[2] Univ Hertfordshire, Sch Life & Med Sci, Hatfield AL10 9AB, Herts - England

• Tipo de documento: Artigo Científico
• Fonte: Polyhedron; v. 211, JAN 1 2022.
• Citações Web of Science: 0

Resumo

The synthesis, characterization, electrochemical and photophysical properties of three novel polypyridine rhenium(I) complexes coordinated to an organoselenide ligand, 4-(phenylseleno)-pyridine (PhSepy), and structurally related polypyridine ligands, fac-{[}Re(CO)(3)(NN)(PhSepy)](+) NN = 1,10-phenanthroline (phen), 4,7-diphenyl-1,10-phenanthroline (ph(2)phen) and pyrazino{[}2,3-f]-1,10-phenanthroline (dpq), are reported. In addition, their ability to act as a photosensitizer agent for the generation of singlet oxygen was investigated. Cyclic and differential pulse voltammetry experiments showed an overlap of the redox waves characteristic of the 4-(phenylseleno)-pyridine ligand and the Re(I) complex. This finding is consistent with a strong contribution of the pyridine-based ligand on the HOMO levels of the three investigated complexes, further supported by quantum mechanical calculations. Moreover, the lowest energy band observed in the absorption spectra of the complexes was also influenced by the organoselenide ligand, with a combination of the usual MLCTRe -> NN transition with a ligand-to-ligand charge transfer (LLCT) one. The three complexes showed typical emission spectra for this class of compounds ascribed to (MLCTRe -> NN)-M-3, with excellent quantum yields for the singlet oxygen generation (phi Delta = 0.65-070). Remarkably, these are significantly larger (15-29%) than those for structurally related complexes with non-functionalized pyridyl ligands, revealing a significant ability as a photosensitizer agent. Therefore, we envisage this work to be of interest to those engaged in the development of novel rhenium(I) complexes for optoelectronic applications. (AU)

• Processo FAPESP: 17/18063-0 - Avaliação de compostos luminescentes de Re(I) em bioimagem e/ou como agentes antitumorais
• Beneficiário: Karina Passalacqua Morelli Frin
• Modalidade de apoio: Auxílio à Pesquisa - Regular